Tony, it all depends upon your needs, I don't play live, I use all my instruments in home studio environment,

so for me softsynths are very manageable on my desktop, I use Sonar X1, Reason 6 along with Live as Host for all my VST's

Omnisphere has huge preset sound library not regular bread and butter sounds but more towards film scores, motion synths,

dance and club sort of genre and in that department preset sounds better than KRONOS presets (check out you tube with Omnisphere and you would know)

I am sure with little effort you can do great sounds with KRONOS using the existing synths I am only reffering to presets.

omnisphere is a complete synthesizer with endless creative possibilities it all depends what kind of music you do and how portable you want your system to be

if you have Tyros 4 and looking for KRONOS then you would have best of both worlds top notch arranger and the best workstation at the moment with 9 synth engines, KARMA and much more...